Fluid pressure brake



Dec. 28, 1937. c. D. STEWART n 2,103,343

FLUID PRESSURE BRAKE Filed sept. 16, 195s f 1 ATTORNEY Patented Dec. 28, 1937 UNITED STATES PATENT oF'Fice FLUID PRESSURE BRAKE* g Carlton D. Stewart, Swissvale, Pa., assignery to, The Westinghouse Air Brake Company, Wil-Y merding, Pa., a corporation ofIennsylYana Application September 16, 1936, Serial Noi-100,997

This invention relates to uid pressure brake equipmentI and more particularly to that type in which there is employed a brake pipe and valve means responsive to a reduction in brake pipe pressure to eiect an application of the brakes and which is responsive to asubsequent increase in brake pipe pressure to elIect the release ofV the brakes.

When a number of such Aequipments are operatively connected together, asin a train, it is very desirable that a reduction in brake pipe pressure, especially in effecting an emergency application of the brakes, be transmitted or propagated as rapidly as possible from one end of the train to the other so as to apply the brakes at the rear end of the train more nearly in synchronism with those at the front end of the train and thereby bring the train to a prompt stop without harsh run in or closing of the slack in the train.

In some classes of passenger train service, one or more electrically controlled traction cars are coupled together to form a train. The brake equipment for each of these cars may include a brake valve device at each end of each car. When' a the cars are coupled together as just noted, the

brakes are normally controlled by the operator through the medium of the brake valve device located at the front end of the head car of the train, the brake valve device on the rear end of the head car and the brake valve devices on each Vof the other cars being in the usual handle-ofi?v position in which they are rendered inoperativeto control the brakes. In this type of car the brake valve devices are arranged a suflicient distance above the car floor to be convenient for manipulation by an operator. Due to this the branch pipe Which connects each brake valve device with the brake pipe must necessarily be of considerable length. The brake equipment for this type of car usually includes a brake controlling valve device, such as a triple valve device, which is adapted to operate according to variations in brake pipe pressure for effecting either an application or the release of the brakes .and may also include a brake pipe ventl valve` device and a conductors brake application.valvedevice, the brake pipe vent valve device beingA adapted .to respond to a reduction in brake pipe pressure initiated through the medium of the brakevalve device to vent uid under pressure from the brake pipe and the conductors brake application valve device being responsive to the operation kof the usual conductors valve to effect the reduction in brake pipe pressureand thereby an. application of the brakes. This latter valve is operated by the conductor only when a dangerous situation arises-of which the operator is vnot aware and is intendedtocause an emergency applica-l tion of the brakes-to be effected.

It has been found that inatrain, such asjust described, the branch pipes which are in vopen communicationvwith thevbrakel pipe and lead therefrom to the brake valvejdevices, brake controlling valve devices, Abrake pipe vent valve devices, and` conductors application'valve devices as well as the piston chamber of the brake controlling valve devices adds so greatly to the Avolume of the lbrake pipe; that the desired rapid propagation` of a brake pipe reduction in'effecting an emergency. application ofthe brakes could not be Obtained due to the back-now of fluid from this added volumejto the brake pipe. In fact, on a train of ten traction cars the 'amount of fluid which flows backfinto the brake pipe from the numerous branch'passages and triple valve i piston chambersA may be great enough to prevent an emergencyreduction inbrake pipe pressure frombeing transmitted tothe'rear cars of the train,'lwith theresult that the slack vin the train iscause'dtorun in or close lharshly andthe train is not brought. to a, stop within a distance commensurate with the safe operation of 'the train. .I

The principal object of the present invention is tov provide an improved iluid pressure brakeV equipment of the above type which will be free of the above mentioned objectionable features.

This Objectis obtained by reducing to a'minimum the length and thereby the volume of all branch pipes which are in openv communication with the brakelpipe and which might have a detrimental iniiuenceon the flow of uid through the brake pipe and` by providing means adapted to restrict the vflow of ,fluid between relatively large chambers and the brake pipe. In brake equipment wherein train service, certain connections, suchas the `connections between the brake pipe andthe .inoperative brake valve devices of thebrake equipment hereinbefore mentioned, are not needed, and, in such equipment the object of theinvention is attainedby cutting off communication between the brake pipe and such connections in additionto maintaining al1 branch connections communicating with the brake pipe as short as possible and. by choking those connections which are in communication with relatively large. chambers. a

Another object of the invention. is to. provide, in afluidpressure brake equipment ofv the type having a brake pipe and one or more fluid conducting pipes or passages which must necessarily be open to the brake pipe in one class of service and which need not be opened in another class of service, means located adjacent the brake pipe and adapted to be controlled from a point remote from the brake pipe for cutting off communica- Ation between the brake pipe and said pipes or passages when the equipment is employed in said other class of service.

In the type of brake equipment employed on traction cars, this object is attained through the medium of a cut-off valve device which is located adjacent the brake pipe and is interposed in the usual branch pipe leading from the brake pipe to a brake valve device and which is preferably operative by iiuid under pressure controlled by a valve located in the operators cab and preferably close to the brake valve device.r

Other objects and advantages will appear in the following more detailed description of the invention. o A

f In the accompanying vdrawing Fig.- 1 is a diagrammatic view ofa'iluid pressure brake equip-VV ment embodying the invention and Fig. 2 is an enlarged detailed sectional view of thecut-off valve device of the equipment. p As shown in Fig. 1 of the drawing the equipment may comprise a control pipe I, a brake pipe 2, Vbrake valve'devices 3 arrangedV one at each end of the equipment,`a brake controlling valve device 4, an auxiliary reservoir 5, a brake cylinder 6, a brake pipe vent valve device "I, .a conductors vent valve device 8, a conductors brake. application valve device 9, two cut-off valve devices III arrangedone at each end of the equipment and two control cocks IIY arranged one at each end of the equipment. v,

The control pipe I is adapted to extend from end to end of a car and at each end is provided with an angle cock I2 to which is secured a iiexible conduit I3 for attachment inthe usual manner with a like conduit of-an adjacent. car when two or more cars arecoupled together. This pipe is connected through a branch pipe I4 with a fluid pressure'supply source, such, for instance, asv the usual feed valve device, not shown, and is also connected byrway of pipes I5 to the brake valve devices 3i The brake pipe 2 also extends from end to end of the car and at each end is provided with an angle cock I 6 to which is secured a. exible conduit I'I for attachment in the usual manner with a like conduit of an adjacent car when two or more cars are coupled together.

It will here be understood that when one car is to be operated as a unit, all of the angle cocks I2 and I6 will be closed and that when a plurality of cars are coupled together to form a train only the angle cocks at the frontend of the head car of the train and those at the rear end of the last car of the train are closed, so that the control pipe and brake pipe will be continuous from end to end of the train.

Y The brake valve devices 3 may each be of the usual construction and may comprise a casing containing a rotary valve, not shown, which is adapted to be moved to its severalv brake controlling positions by means of the usual handle I8 which is removably applied to the rotatable stem I9 of the valve. It will here be understood that when the car is to be operated as a unit, the brake valve device at the rear end ofthe car will be in handle off position and the handle removed, and that when a plurality of cars are coupled together to form a train all of the brake valve devices, with the exception of the one at the front end of the head car of the train, will be in handle oi position and the handles removed. Y

The brake controlling valve device 4 shown in the present embodiment ofthe invention, is in the form of the usual triple valve device and is operative upon a reduction in brake pipe pressure to supply fluid under'pressure from the auxiliary reservoir 5 to theV brake' cylinder 6 to effect an application of the brakes and upon a subsequent' increase in brake pipe pressure to release fluid under pressure from the brake cylinder to effect the release of the brakes. 'I'his device is placed as close to the brake pipe as the construction of the car body will permit and is connected through a branch pipe I9 to the brake pipe, the loW area of the pipe I9 being restricted at a point very close to the brake pipe as indicated in Fig. 1 by thereference character 2|.V

and 22, respectively, the devicesbeing placedVv as close to the brake pipe as possible ,so that the pipes 2| and 22 Will be of thewshortest possible length. Y

y The conductors valve device 8 is of theusual construction and is connected to the ,brakefapplication valve device through the usual con-`A trol pipe 23.

Each cut-off valve device I0 is placedve'ry close to the brake pipe and comprises'acasing having a passage 26 which is connected through a very short piece of pipe 2l to the brake pipe and also having a passage 28 which is connected througha pipe V29 to the brake valve device at one end of .thefcan Communication between these passages 26 and 28 is adapted to be controlled by a flexible diaphragm. valve 3D which is mounted in the casing. kThe operation of this diaphragm valve is adapted to be controlled by a flexible diaphragm 3| mounted in the casing, which diaphragm acts on the valve through the medium of a follower 32 interposed between and operatively engaging the diaphragm` .valve :351) and diaphragm` 32.

At one side of the flexible diaphragm 32 there is a chamber 33 which isl adapted to be vconnected to the branch pipe I 5 by way of a passage it is shown at the left hand end of this figure,

the valve in the rst mentioned position establishing communication between the pipes 35 and 36 and consequently between the control pipe and the diaphragm chamber 32 of the cut-off valve device I Il, and in its other position establishing communication from the pipe 35 and thereby the chamber 33 with the atmosphere by way of an exhaust port 38. When a plurality of vcars are coupled together in a train the valve devic'efl'l y at the front end ofthe head car of the train -`In operation, in :initially charging the equip# 1 each end of the car to the brake valve devices 3.

With the brake valve device 3 at the front end of the head car of the train in release position as shown in Fig. 1, the-rotary valve of the brake valve device is adapted to establish communication between the pipe I5 and the pipe 29 so that uid under pressure being supplied through pipe I5 flows through pipe 29, passage 28 of the cutoi` valve device IIJ, past the unseated diaphragm valve 30 and through passage 26 and short pipe 21 to the brake pipe 2. It will here be noted that since the control valve device II at the front end ofthe car is in position connecting the diaphragm chamber 33 of the cut-oir valve device to the atmosphere the diaphragm'valve 30 will be maintained unseated by fluid under pressure in chambers 28 and 26. At the rear end of the car the control Valve device II establishes communication between the pipes 35 and 36 so that huid under pressure supplied to the pipe I5 at the rear end of the car ows to the diaphragm chamber 33 of theassociated cut-Off valve device I0, and causes the diaphragm to flex and seat the diaphragm valve 30, so as to cut o communication between the passages 28 and 26 and consequently between the pipe 29 and the brake pipe 2. Since the valve devices I I on the other cars of the train are Ain the same position as the valve at the rear end of the iirst car of the train, all of the branch pipes 29 Will be isolated from the brake pipe 2. Fluid under pressure continues to flow through the cut-off valve device I0 at the front end of the ca r and pipe 2'I until the brake pipe and associated chambers are fully charged to the desired pressure.

- When it is desired to effect an emergency application of the brakes, the brake valve device 3 at the front end of the head car of the train is moved, through the medium of the handle I8, to emergency position in which uid under pressure is vented from the brake pipe at an emergency rate for the purpose of causing the triple valve devices on each car to move to emergency application position. The brake pipe vent valve device 1 on each car responds to this reduction to effect a local reduction in brake pipe pressure so asv to propagate the reduction in brake pipe pressure rapidly throughout the length of the train. It will here be noted that since all but one of the long pipes 29 are isolated from the brake pipe and the branch pipes 20, 22 and 23 are very short and since, in addition, the passage 20 is restricted at a point close to the brake pipe, the back-o-W of fluid from said passages to the brake pipe Will be so minimized that it Will have no material retarding effect upon the transmission of the emergency rate of reduction in brake pipe pressure.

In practice it has been found on a train embodying the invention, that the emergency action is propagated throughout the entire length of the train and that the propagation rate of such action is much more rapid than has heretofore been possible.

It will be apparent from the foregoing description that invention not only serves to increase the rate of transmission and the eiectveness of an emergency reduction in brake pipe pressure but also serves to increase the rate of transmission and electiveness of a service reduction in brake pipe pressure, and obviously further provides for a more rapid charging of the equipment.

While one illustrative embodiment of the invention has been described in detail, itis not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a uid pressure'brake equipment, in combination, a brake pipe, a reduction in the pressure of which brake pipe is adapted to cause the equip: ment to operateV to effect an application of the brakes a plurality of brake controlling valve devices for controlling an application of the brakes, connectionsfrom said brake pipe to said devices, some of said connections being of minimum length, others, which lead from relatively large volumes, being of minimum length and being restricted at a point'close to the brake pipe -and others of greater length and unnecessary in certain brakingr operations being adapted to becut off from the brake pipe, all of which combined minimizes the amount and rate of back-now of fluid from said devices to the-brake pipe upon a reduction in brake pipe pressure and thereby minimizes the detrimental eiect back-ilow'o fluid may have on the transmission of the reduction in brake pipe pressure throughout a plurality of operatively connected brakeequipments.

2. In a uid pressure brake equipment, in combination, a brake pipe, a reduction in the pressure of which brake pipe is adapted to cause the equipment tooperate to effect an application of the brakes, a plurality of rbrake controlling valve devices for controlling an application of the brakes connections from saidbrake 'pipe to said devices, some of said connections being of minimum length, others, which lead from a relatively large volume, being of minimum length and being restricted at a point close to the brakepipe and others of-greater length and unnecessary when a plurality of the equipments are operatively connected together, as in a train, being cut off from the brake pipe', all of Which combined minimizes the amount and rate of back-flow of fluid from f said devicesto thev brake pipe upon a reduction in brake pipe pressure and thereby minimizes the detrimental effect back-ow of fluid may have on the transmission of the reduction in brake pipe pressure throughout al plurality of operatively connected brake equipments.V

3. In a fluid pressure brake equipment, in combination, a brake pipe, a reduction in the pressure of which brake pipe is adapted to cause the equipment to operate to effect an application of the brakes, a plurality of brake controlling valve devices for controlling an application of the brakes, connections from said brake pipe to said devices, some of said connections'being of minimum length, others, which lead from a relatively large Volume, being of minimum length and being restricted at a point close to the brake pipe and others of greater length. and unnecessary when a plurality of the equipments are operatively connected together, as in a train, being adapted to be cut o-i from the brake pipe all of which combined minimizes the amount and rate of back-flow of fluid from said devices to the brake pipe upon a reduction in brake pipe pressure and thereby minimizes the detrimental effect back-flow of fluid may have on the transmission of the reduction in brake pipe pressure throughout a plurality of operatively connected brake equipments, valve devices arranged close to the brake pipe and operative to cut olf the last 75 mentioned connections from the brake pipe, and means remotely positioned with relation to said valve devices and operative to effect the operation Y of the devices. Y

4. In a iiuid pressure brake equipmentfor cars of a train and comprising a vbrake pipe adapted to be connected to the brake pipe of an;

adjacent vehicle of the train, a reduction in the pressure of iiuid in the Abrake pipe being adapted to cause an application Vof the brakes to be effected, said equipment having at least one fluid conducting communication connected to the brake pipe which'is unnecessary in train service, and means included in theequipment operable to cut 01T said communication at a, point close to,

the brake pipe. ,e

5. In a fluid pressure brake equipment forV cars of atrain and comprising brake pipeadapted to be connected to the brake pipe of an adjacent vehicle of the train, a reduction in the pressure -ofto be connected to the brake pipe of an adjacent` vehicle of the train, a reduction in the pressure of Which continuous brake pipe causes an application of the brakes to be effected, said equipment having at least one fiuid conducting,communication connected to the brake pipe which is'necessary in single car operation and unnecessary in train operation, iiuid pressure controlled means included in the equipment operable to cut off said communication close to the brake pipe, and valve means located remotely with relation to the valve means operable to control the operation of said Y valve means. Y Y

7. In a fiuid pressure brake equipment for a vehicle, in combination, a brake pipe extending from end to end of the vehicle, a reduction in the pressure of which brake pipe is adapted t cause an application of the brakes to be eiected, a brake valve device, a fluid conducting pipe through YWhich said brake-valvedevice is adapted to supply fluid under pressure to and release fiuid'under pressure from the brake pipe, a controlling valve device disposed closely'adjacent the brake pipe for controlling;communication through said fiuid conducting pipe, and means disposed for convenience of operation by the operator for controlling the operation of said controlling valve device. y f f 8.v In a fluid pressure brake equipment for a vehicle, in combination, a brake pipe extending from end to end of the vehicle, a reduction in the pressure of` which 'brake pipe is adapted to cause an application of the, brakes to be effected, a brake valve device, a uid conducting pipe through which saidVv brake valve device is adapted to supply fluid under pressure to and release fluid under pressure from the-brake pipe, a controlling valve device disposed closely adjacent the brake pipe and operativeA by fluid under pressure for closing communication through said fluid conducting pipe, and manually operable valve means disposed for convenience of operation by an operator for varying the fluid pressure on said controlling valve device.

. A9. In a fluid pressure brake equipment, in combination, a brake pipe, a brake valve device operative to -vary the fluid pressure in said pipe, a controlling valve device disposed closely adjacent to said pipe for controlling communication Y through which said brake valve device supplies fluid to the brake pipe, manually operable means disposed adjacent to thebrake valve device for controlling the operation ofk saidcontrolling valve device, a brake controlling valve device operative upon a reduction in brake pipe pressure for effectingan applicationof the brakes, communication througliwhich brake pipe pressure on said brake controlling valve device is varied being restricted closely adjacent to the brake pipe, a valve device disposed closely adjace-nt to vthe brake pipe and operated by a variation in fluid pressure for venting fluid from the brake pipe, a conductors valve device for varying the fluid pressure on said last named valve device, and a brake pipe-vent valve device disposed closely adjacent to said brake pipe and substantially midway of the brake pipe on the vehicle and operative upon a sudden reduction in brake pipe pressure forlocally venting the brake pipe. f

CARLTON D. STEWART.r 

